POS0698 REAPPRAISAL OF LARGE ARTERY INVOLVEMENT IN GIANT CELL ARTERITIS, A POPULATION-BASED COHORT OVER 70 YEARS
Authors: M. Elfishawi, M. Kaymakci, S. Achenbach, C. S. Crowson, T. Kermani, W. Cornelia, M. Koster, K. J. Warrington
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Screening for large artery manifestations in patients with Giant Cell Arteritis (GCA) has been adopted in clinical practice. However, the effect of recent use of imaging studies on incidence and mortality of large artery manifestations remains unclear. <h3>Objectives</h3> In this study, we aimed to investigate incidence trends and outcomes of large artery manifestations in a population-based cohort of patients with GCA over a span of seven decades. <h3>Methods</h3> The study cohort included patients with incident GCA between 1950-2016 in a defined geographical area. Incident large artery manifestations were defined as aortic aneurysm, aortic dissection, stenosis in the aorta or any of its main branches diagnosed within 1 year prior to the diagnosis of GCA or anytime afterwards. Patients were followed till December 31<sup>st</sup>, 2020, death, or migration. Cumulative incidence of large artery manifestations adjusted for the competing risk of death was estimated. Cox proportional hazards models adjusted for age and sex were used to assess the association of clinical characteristics with large artery manifestations. <h3>Results</h3> The study included 289 patients with GCA: 222 (77%) females; temporal artery biopsy was positive in 235 patients (81%); mean follow up period was 10.4 ± 7 years; mean age at diagnosis was 76.4 ± 8.2 years. Incident large artery manifestations developed in 104 patients throughout the follow up period, the majority (76%) were found incidentally. Cumulative incidence rates of large artery manifestations at 5 years were 7.3% (95% CI 2.4-22.1%), 15.9% (95% CI 10.6-23.8%) and 27.2% (95% CI 20.2-36.6) for patients diagnosed in 1950-1974, 1975-1999 and 2000-2016, respectively. Moreover, cumulative incidence of large vessel manifestations at 15 years was 14.8% (95% CI 7.0-31.6%), 30.2% (95% CI 23.1-39.4%) and 48.8% (95% CI 38.8-61.3%) for patients diagnosed in 1950-1974, 1975-1999 and 2000-2016, respectively (Figure 1). Patients with GCA diagnosed in 2000-2016 and 1975-1999 had more than 3.5-fold and 2-fold increase in incidence of large artery manifestations (HR:3.49 95%CI 1.67-7.3 and HR: 1.98 95% CI 0.97–4.07, respectively) compared to 1950-1974. However, there was no significant increase in aortic aneurysm or dissection (Table 1). Mortality risk has decreased significantly in patients with large artery manifestations diagnosed in the latest cohort 2000-2016 (HR 0.38 95% CI 0.17–0.81) following non-significant improvements in 1975-1999 (HR 0.61 95% CI 0.29-1.30) compared to 1950-1974 (reference). Clinical predictors for large artery manifestations included weight loss, fatigue, arm claudication, ever smoker and bruit on physical examination. Cranial symptoms were negatively associated with large artery manifestations. <h3>Conclusion</h3> Incidence of large artery manifestations (mainly large artery stenosis) has increased over time likely from increased use of imaging studies. However, the incidence of aortic aneurysm/dissection has been stable over the last 7 decades. Mortality improvement in the recent years may be due to earlier detection of large artery involvement. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Mohanad Elfishawi: None declared, Mahmut Kaymakci: None declared, Sara Achenbach: None declared, Cynthia S. Crowson: None declared, Tanaz Kermani: None declared, Weyand Cornelia: None declared, Matthew Koster: None declared, Kenneth J Warrington Consultant of: Chemocentryx, Sanofi, Grant/research support from: Eli Lilly, Kiniksa, GSK.